[hb-cairo] Make hb_cairo_glyphs_from_buffer public

src/hb-cairo.cc

@@ -30,6 +30,8 @@
 
 #include "hb-cairo-utils.hh"
 
+#include "hb-utf.hh"
+
 static void
 move_to (hb_draw_funcs_t *dfuncs,
          cairo_t *cr,
@@ -395,3 +397,126 @@ hb_cairo_font_face_get_font (cairo_font_face_t *font_face)
 {
   return (hb_font_t *) cairo_font_face_get_user_data (font_face, &hb_cairo_font_user_data_key);
 }
+
+
+void
+hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
+			     const char *text,
+			     int text_len,
+			     hb_bool_t utf8_clusters,
+			     int scale_factor,
+			     cairo_glyph_t **glyphs,
+			     unsigned int *num_glyphs,
+			     cairo_text_cluster_t **clusters,
+			     unsigned int *num_clusters,
+			     cairo_text_cluster_flags_t *cluster_flags)
+{
+  if (text && text_len < 0)
+    text_len = strlen (text);
+
+  *num_glyphs = hb_buffer_get_length (buffer);
+  hb_glyph_info_t *hb_glyph = hb_buffer_get_glyph_infos (buffer, nullptr);
+  hb_glyph_position_t *hb_position = hb_buffer_get_glyph_positions (buffer, nullptr);
+  *glyphs = cairo_glyph_allocate (*num_glyphs + 1);
+
+  if (text)
+  {
+    *num_clusters = *num_glyphs ? 1 : 0;
+    for (unsigned int i = 1; i < *num_glyphs; i++)
+      if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
+	(*num_clusters)++;
+    *clusters = cairo_text_cluster_allocate (*num_clusters);
+  }
+  else if (clusters)
+  {
+    *clusters = nullptr;
+    *num_clusters = 0;
+    *cluster_flags = (cairo_text_cluster_flags_t) 0;
+  }
+
+  if ((*num_glyphs && !*glyphs) ||
+      (clusters && *num_clusters && !*clusters))
+  {
+    if (*glyphs)
+    {
+      cairo_glyph_free (*glyphs);
+      *glyphs = nullptr;
+      *num_glyphs = 0;
+    }
+    if (clusters && *clusters)
+    {
+      cairo_text_cluster_free (*clusters);
+      *clusters = nullptr;
+      *num_clusters = 0;
+      *cluster_flags = (cairo_text_cluster_flags_t) 0;
+    }
+    return;
+  }
+
+  double iscale = scale_factor ? 1. / scale_factor : 0.;
+  hb_position_t x = 0, y = 0;
+  int i;
+  for (i = 0; i < (int) *num_glyphs; i++)
+  {
+    (*glyphs)[i].index = hb_glyph[i].codepoint;
+    (*glyphs)[i].x = (+hb_position->x_offset + x) * iscale;
+    (*glyphs)[i].y = (-hb_position->y_offset + y) * iscale;
+    x +=  hb_position->x_advance;
+    y += -hb_position->y_advance;
+
+    hb_position++;
+  }
+  (*glyphs)[i].index = -1;
+  (*glyphs)[i].x = x * iscale;
+  (*glyphs)[i].y = y * iscale;
+
+  if (*num_clusters)
+  {
+    memset ((void *) *clusters, 0, *num_clusters * sizeof ((*clusters)[0]));
+    hb_bool_t backward = HB_DIRECTION_IS_BACKWARD (hb_buffer_get_direction (buffer));
+    *cluster_flags = backward ? CAIRO_TEXT_CLUSTER_FLAG_BACKWARD : (cairo_text_cluster_flags_t) 0;
+    unsigned int cluster = 0;
+    const char *start = text, *end;
+    (*clusters)[cluster].num_glyphs++;
+    if (backward)
+    {
+      for (i = *num_glyphs - 2; i >= 0; i--)
+      {
+	if (hb_glyph[i].cluster != hb_glyph[i+1].cluster)
+	{
+	  assert (hb_glyph[i].cluster > hb_glyph[i+1].cluster);
+	  if (utf8_clusters)
+	    end = start + hb_glyph[i].cluster - hb_glyph[i+1].cluster;
+	  else
+	    end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start,
+								      (signed) (hb_glyph[i].cluster - hb_glyph[i+1].cluster));
+	  (*clusters)[cluster].num_bytes = end - start;
+	  start = end;
+	  cluster++;
+	}
+	(*clusters)[cluster].num_glyphs++;
+      }
+      (*clusters)[cluster].num_bytes = text + text_len - start;
+    }
+    else
+    {
+      for (i = 1; i < (int) *num_glyphs; i++)
+      {
+	if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
+	{
+	  assert (hb_glyph[i].cluster > hb_glyph[i-1].cluster);
+	  if (utf8_clusters)
+	    end = start + hb_glyph[i].cluster - hb_glyph[i-1].cluster;
+	  else
+	    end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start,
+								      (signed) (hb_glyph[i].cluster - hb_glyph[i-1].cluster));
+	  (*clusters)[cluster].num_bytes = end - start;
+	  start = end;
+	  cluster++;
+	}
+	(*clusters)[cluster].num_glyphs++;
+      }
+      (*clusters)[cluster].num_bytes = text + text_len - start;
+    }
+  }
+}

src/hb-cairo.h

@@ -39,6 +39,18 @@ hb_cairo_font_face_create (hb_font_t *font);
 HB_EXTERN hb_font_t *
 hb_cairo_font_face_get_font (cairo_font_face_t *font_face);
 
+HB_EXTERN void
+hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
+			     const char *text,
+			     int text_len,
+			     hb_bool_t utf8_clusters,
+			     int scale_factor,
+			     cairo_glyph_t **glyphs,
+			     unsigned int *num_glyphs,
+			     cairo_text_cluster_t **clusters,
+			     unsigned int *num_clusters,
+			     cairo_text_cluster_flags_t *cluster_flags);
+
 HB_END_DECLS
 
 #endif /* HB_CAIRO_H */

src/hb-utf.hh

@@ -35,6 +35,7 @@
 struct hb_utf8_t
 {
   typedef uint8_t codepoint_t;
+  static constexpr unsigned max_len = 4;
 
   static const codepoint_t *
   next (const codepoint_t *text,
@@ -182,6 +183,7 @@ struct hb_utf16_xe_t
 {
   static_assert (sizeof (TCodepoint) == 2, "");
   typedef TCodepoint codepoint_t;
+  static constexpr unsigned max_len = 2;
 
   static const codepoint_t *
   next (const codepoint_t *text,
@@ -290,6 +292,7 @@ struct hb_utf32_xe_t
 {
   static_assert (sizeof (TCodepoint) == 4, "");
   typedef TCodepoint codepoint_t;
+  static constexpr unsigned max_len = 1;
 
   static const TCodepoint *
   next (const TCodepoint *text,
@@ -348,6 +351,7 @@ typedef hb_utf32_xe_t<uint32_t, false> hb_utf32_novalidate_t;
 struct hb_latin1_t
 {
   typedef uint8_t codepoint_t;
+  static constexpr unsigned max_len = 1;
 
   static const codepoint_t *
   next (const codepoint_t *text,
@@ -399,12 +403,13 @@ struct hb_latin1_t
 struct hb_ascii_t
 {
   typedef uint8_t codepoint_t;
+  static constexpr unsigned max_len = 1;
 
   static const codepoint_t *
   next (const codepoint_t *text,
 	const codepoint_t *end HB_UNUSED,
 	hb_codepoint_t *unicode,
-	hb_codepoint_t replacement HB_UNUSED)
+	hb_codepoint_t replacement)
   {
     *unicode = *text++;
     if (*unicode >= 0x0080u)
@@ -450,4 +455,27 @@ struct hb_ascii_t
   }
 };
 
+template <typename utf_t>
+static inline const typename utf_t::codepoint_t *
+hb_utf_offset_to_pointer (const typename utf_t::codepoint_t *start,
+			  signed offset)
+{
+  hb_codepoint_t unicode;
+
+  while (offset-- > 0)
+    start = utf_t::next (start,
+			 start + utf_t::max_len,
+			 &unicode,
+			 HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT);
+
+  while (offset++ < 0)
+    start = utf_t::prev (start,
+			 start - utf_t::max_len,
+			 &unicode,
+			 HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT);
+
+  return start;
+}
+
+
 #endif /* HB_UTF_HH */

util/helper-cairo.hh

@@ -592,127 +592,6 @@ struct helper_cairo_line_t {
   }
 };
 
-static inline void
-hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
-			     const char *text,
-			     int text_len,
-			     hb_bool_t utf8_clusters,
-			     int scale,
-			     cairo_glyph_t **glyphs,
-			     unsigned int *num_glyphs,
-			     cairo_text_cluster_t **clusters,
-			     unsigned int *num_clusters,
-			     cairo_text_cluster_flags_t *cluster_flags)
-{
-  if (text && text_len < 0)
-    text_len = strlen (text);
-
-  *num_glyphs = hb_buffer_get_length (buffer);
-  hb_glyph_info_t *hb_glyph = hb_buffer_get_glyph_infos (buffer, nullptr);
-  hb_glyph_position_t *hb_position = hb_buffer_get_glyph_positions (buffer, nullptr);
-  *glyphs = cairo_glyph_allocate (*num_glyphs + 1);
-
-  if (text)
-  {
-    *num_clusters = *num_glyphs ? 1 : 0;
-    for (unsigned int i = 1; i < *num_glyphs; i++)
-      if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
-	(*num_clusters)++;
-    *clusters = cairo_text_cluster_allocate (*num_clusters);
-  }
-  else if (clusters)
-  {
-    *clusters = nullptr;
-    *num_clusters = 0;
-    *cluster_flags = (cairo_text_cluster_flags_t) 0;
-  }
-
-  if ((*num_glyphs && !*glyphs) ||
-      (clusters && *num_clusters && !*clusters))
-  {
-    if (*glyphs)
-    {
-      cairo_glyph_free (*glyphs);
-      *glyphs = nullptr;
-      *num_glyphs = 0;
-    }
-    if (clusters && *clusters)
-    {
-      cairo_text_cluster_free (*clusters);
-      *clusters = nullptr;
-      *num_clusters = 0;
-      *cluster_flags = (cairo_text_cluster_flags_t) 0;
-    }
-    return;
-  }
-
-  double iscale = scale ? 1. / scale : 0.;
-  hb_position_t x = 0, y = 0;
-  int i;
-  for (i = 0; i < (int) *num_glyphs; i++)
-  {
-    (*glyphs)[i].index = hb_glyph[i].codepoint;
-    (*glyphs)[i].x = (+hb_position->x_offset + x) * iscale;
-    (*glyphs)[i].y = (-hb_position->y_offset + y) * iscale;
-    x +=  hb_position->x_advance;
-    y += -hb_position->y_advance;
-
-    hb_position++;
-  }
-  (*glyphs)[i].index = -1;
-  (*glyphs)[i].x = x * iscale;
-  (*glyphs)[i].y = y * iscale;
-
-  if (*num_clusters)
-  {
-    memset ((void *) *clusters, 0, *num_clusters * sizeof ((*clusters)[0]));
-    hb_bool_t backward = HB_DIRECTION_IS_BACKWARD (hb_buffer_get_direction (buffer));
-    *cluster_flags = backward ? CAIRO_TEXT_CLUSTER_FLAG_BACKWARD : (cairo_text_cluster_flags_t) 0;
-    unsigned int cluster = 0;
-    const char *start = text, *end;
-    (*clusters)[cluster].num_glyphs++;
-    if (backward)
-    {
-      for (i = *num_glyphs - 2; i >= 0; i--)
-      {
-	if (hb_glyph[i].cluster != hb_glyph[i+1].cluster)
-	{
-	  assert (hb_glyph[i].cluster > hb_glyph[i+1].cluster);
-	  if (utf8_clusters)
-	    end = start + hb_glyph[i].cluster - hb_glyph[i+1].cluster;
-	  else
-	    end = g_utf8_offset_to_pointer (start, hb_glyph[i].cluster - hb_glyph[i+1].cluster);
-	  (*clusters)[cluster].num_bytes = end - start;
-	  start = end;
-	  cluster++;
-	}
-	(*clusters)[cluster].num_glyphs++;
-      }
-      (*clusters)[cluster].num_bytes = text + text_len - start;
-    }
-    else
-    {
-      for (i = 1; i < (int) *num_glyphs; i++)
-      {
-	if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
-	{
-	  assert (hb_glyph[i].cluster > hb_glyph[i-1].cluster);
-	  if (utf8_clusters)
-	    end = start + hb_glyph[i].cluster - hb_glyph[i-1].cluster;
-	  else
-	    end = g_utf8_offset_to_pointer (start, hb_glyph[i].cluster - hb_glyph[i-1].cluster);
-	  (*clusters)[cluster].num_bytes = end - start;
-	  start = end;
-	  cluster++;
-	}
-	(*clusters)[cluster].num_glyphs++;
-      }
-      (*clusters)[cluster].num_bytes = text + text_len - start;
-    }
-  }
-}
-
-
 static inline void
 helper_cairo_line_from_buffer (helper_cairo_line_t *l,
 			       hb_buffer_t         *buffer,